Historically, keeping backyard chickens was a response to economic hardship — whether it was in the Great Depression or during wartime food rationing. However, an increasing number of chickens today are roaming or are caged on small family farms and in back yards as suburban and urban poultry gains more popularity among consumers, according to an announcement from the University of California-Davis.

Many people prefer to raise their own food because they think it will be safer, fresher and more nutritious than the same commercially raised foods. Yet, a new University of California-Davis study suggests that local ordinances are not adequately addressing human and animal health when it comes to backyard poultry, and laws that do exist do not keep pace with those for commercial growers.

“Ironically, as people seek to take control over the way their food is grown, most ordinances fail to ensure basic health and welfare for birds and humans,” said Catherine Brinkley, assistant professor of community and regional development in the university's College of Agricultural & Environmental Sciences and the primary author of the study.

The paper, “A Method for Guarding Animal Welfare & Public Health: Tracking the Rise of Backyard Poultry Ordinances,” was published recently in the Journal of Community Health.

What needs to happen, Brinkley recommended, is that there be more laws that mandate vaccinations, manure management and general animal welfare in urban and suburban settings, similar to policies and regulations imposed on commercial chicken ranches.

“Provisions governing animal slaughter and routine veterinary care are rare, presenting a concern for monitoring and intervening in public health crises,” the paper says. “In addition, shelters anticipate higher poultry intakes, particularly as unwanted birds are turned loose to become strays.”

The researchers focused their study on 100 municipalities in Colorado, the only state to compile public data for animal shelter surrenders and other statistics. Compared with three other U.S. cities — Los Angeles, Cal.; Miami, Fla., and New York, N.Y. — Denver, Colo., had the highest percentage of respondents in favor of allowing backyard poultry -- at 62.5% -- and the lowest percentage of respondents who believed urban poultry would lead to more human disease, at 7.4%. Almost 42,000 households across the four cities were surveyed.

Almost all of the laws governing poultry keeping in Colorado were passed after 2000.

“More poultry ordinances have been passed or modified in Colorado in the last five years than in the previous hundred,” Brinkley said.

The researchers determined that the most common guidelines for poultry ordinances pertain to housing design, placement and the sex of birds; some municipalities ban roosters altogether, while some do not, and still others permit one rooster per 12 hens, for example. However, regulations pertaining to cleanliness, ventilation and food and water requirements are often lacking. Ordinances governing the slaughter of backyard chickens occur in only half of municipalities in Colorado, and many are vague, the researchers found.

Regulations pertaining to the chickens’ health and welfare were rare in the Colorado study, with only 2% of municipalities including poultry under animal cruelty and abuse regulations, according to the announcement.